Machine Kinematics

Mechanism

Question 1
Marks : +2 | -2
Pass Ratio : 100%
The Grubler’s criterion for determining the degrees of freedom (n) of a mechanism having plane motion is
n = (l – 1) – j
n = 2(l – 1) – 2j
n = 3(l – 1) – 2j
n = 4(l – 1) – 3j
Explanation:
None
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Whitworth quick return motion mechanism consists of three turning pairs and one sliding pair.
True
False
Explanation:
Whitworth quick return motion mechanism is a form of single slider crank chain and it consists of one sliding pair and three turning pairs.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
In a coupling rod of a locomotive, each of the four pairs is a _____________ pair.
sliding
turning
rolling
screw
Explanation:
In a locomotive, one rod of the coupling rod can only turn or revolve about a fixed axis of another rod. This takes place only in case of turning pair.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
The whitworth quick return motion mechanism is formed in a slider crank chain when the
coupler link is fixed
longest link is a fixed link
slider is a fixed link
smallest link is a fixed link
Explanation:
None.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
In a single slider crank chain
each of the four pairs is a turning pair
one is a turning pair and three are sliding pairs
two are turning pairs and two are sliding pairs
three are turning pairs and one is a sliding pair
Explanation:
Single slider crank chain consists of one sliding pair and three turning pairs.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
The mechanism forms a structure, when the number of degrees of freedom (n) is equal to
0
1
2
-1
Explanation:
A structure can be formed only when the number of degrees of freedom is zero.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
In a four bar chain or quadric cycle chain
each of the four pairs is a turning pair
one is a turning pair and three are sliding pairs
two are turning pairs and two are sliding pairs
three are turning pairs and one is a sliding pair
Explanation:
Four bar chain or quadric cycle chain consists of four links, each of them forms a turning pair.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
The inversion of a mechanism is
changing of a higher pair to a lower pair
turning its upside down
obtained by fixing different links in a kinematic chain
obtained by reversing the input and output motion
Explanation:
We can obtain as many mechanisms as the number of links in kinematic chain by fixing, in turn,different links in a kinematic chain. This method is known as inversion of the mechanism.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is an inversion of a single slider crank chain?
Pendulum pump or Bull engine
Rotary internal combustion engine
Oscillating cylinder engine
Crank and slotted lever quick return motion mechanism
Explanation:
All the mechanisms mentioned above are forms of single slider crank chain only and hence, they all contain three turning pairs and one sliding pair. The inversion of a single slider crank chain are found in the following mechanism:
Question 10
Marks : +2 | -2
Pass Ratio : 100%
A type-writer constitutes a machine.
True
False
Explanation:
When a mechanism is required to transmit power or to do some particular type of work, it then becomes a machine.But in case of a typewriter there is no case of power transmission. Hence it is not a machine.